1. Field of the Invention
The present invention relates to a data communication system and an address setting method for setting an internet protocol (IP) address to an apparatus which exists beyond a router.
2. Description of the Related Art
When connecting a new apparatus to a network, it is necessary to set an IP address to enable the apparatus to perform suitable communication on the network. Further, in communication between different subnets, apparatuses can communicate with each other via a router. A technique discussed in Japanese Patent Application Laid-Open No. 2001-285305 is known as a conventional technique for setting an IP address to an apparatus connected to a network environment having different subnets. The technique discussed in Japanese Patent Application Laid-Open No. 2001-285305 acquires a media access control (MAC) address of an apparatus subjected to IP address setting by using a multicast packet, and sets an IP address to the apparatus.
However, the technique discussed in Japanese Patent Application Laid-Open No. 2001-285305 is based on the premise that a host can receive a reply to a multicast packet from a printer subjected to IP address setting. However, some routers do not transfer a reply to a multicast packet from an apparatus having no valid IP address setting. Therefore, under such an environment, the technique discussed in Japanese Patent Application Laid-Open No. 2001-285305 cannot set an IP address to an apparatus connected to a different subnet network.